1. Field of the Invention
The invention relates to an optoelectronic sensor device with a housing, especially an optical proximity switch, such as a reflex light momentary contact switch or a sensor device for a one-way or reflected light photoelectric barrier. These optical proximity switches have light-emitting components, typically diodes, and preferably laser diodes as the transmitting components. Receiving components are generally large-area photodiodes. These optical proximity switches can be divided essentially into three different types, specifically into one-way systems, reflection systems, and momentary contact switch systems.
2. Description of Related Art
One way systems consist, on the one hand, of a transmitter device, and on the other, of a receiver device which is spatially separate from it. The transmitter device and the receiver device are arranged opposite one another on the side boundaries of the area to be monitored, such that light emitted by the transmitter device can be received by the receiver device. In contrast, in reflection systems, the transmitters and receivers are integrated into a single unit, therefore a single device. One such unit which represents a transmitter/receiver device is located on the outer boundary of the area to be monitored, while on the other boundary of the area to be monitored, which is opposite it, there is a reflector which reflects back the light emitted by the transmitter/receiver device onto it such that it can be received by the receiver which is integrated into the transmitter/receiver device. It is common to the two above described systems that the receiver does not receive a light signal or at least receives a reduced light signal when an object is located in the area to be monitored, since this object completely or at least partially interrupts the beam path of the light emitted by the transmitter.
Basically, different from this mode of operation is the mode of operation of optoelectronic momentary contact switch systems. In these systems, the transmitter and the receiver are, likewise, together in one unit, but there is no reflector as a component of the system. Instead, the light emitted by the transmitter in the transmitter/receiver device is reflected on the object to be detected. If at least part of this light reflected on the object to be detected is incident back on the transmitter/receiver device, this reflected light portion can be detected by the receiver.
However, in all three types of optoelectronic sensor systems, it is necessary to exactly align the optoelectronic sensor devices during their installation so that the light emitted by the transmitter is incident either directly or via reflection on the receiver. In addition, it can be necessary for the optoelectronic sensor device to be mounted in an area of the system which is only poorly accessible and/or offers only little space for mounting.
In particular, if only little space is available for the installation of the optoelectronic sensor device, and under certain circumstances, there is only one possible arrangement or orientation of the optoelectronic sensor device, it is desirable to have an optoelectronic sensor device which enables emission of light in different directions or reception of light from different directions. Accordingly, in one such optoelectronic sensor device the orientation of the transmitting and receiving unit can be adapted accordingly. At least it must be ensured that, in terms of external shape, essentially the same optoelectronic sensor devices are available in which there are receiving and transmitting units on different sides. But here, for production engineering reasons and reasons of storage, it is desirable not to produce a host of different optoelectronic sensor devices and to have to store them in order to meet the aforementioned requirements.
German Patents DE 32 22 954 C2 and DE 196 09 238 C2 disclose optoelectronic sensor devices in which, on the housing of the optoelectronic sensor device, there is a housing attachment which can be turned relative to the housing, and in this way, enables emission or reception of light from different directions. Admittedly, with these optoelectronic sensor devices, in the installed state, adaption to the spatial installation and transmitting and receiving conditions can be achieved, but these optoelectronic sensor devices are not compact devices as a result of the additional attachment. The additional attachment is, moreover, mechanically complex and susceptible to damage.
Accordingly, a primary object of the present invention is to devise an optoelectronic sensor device which can be produced as a compact unit and with the same external dimensions can be matched to different installation situations, especially can have the receiver or the transmitter on different sides.
The optoelectronic sensor device in accordance with the invention which achieves the aforementioned object is characterized in that, in the housing, there are an optics module and an electronics module. Therefore, this means that the housing, on the one hand, has an optics module for holding optical components, such as polarizers, lenses, mirrors, and diaphragms, and on the other hand, has an electronics module which has the electronics necessary for the optoelectronic sensor device so that the optics module is free of electronic components.
By separating and dividing the components necessary for the optoelectronic sensor device into the optics module, on the one hand, and the electronics module, on the other, a type of modular system is accomplished. This means that, depending on the requirements for the optoelectronic sensor devices, especially depending on the direction of light emission or reception which is necessary based on the installation situation of the optoelectronic sensor devices, at outside dimensions which are the same each time, specifically with the same housing, optoelectronic sensor devices with a transmitter and a receiver on different sides are available, and they can be produced from a small number of components which can be installed differently. In the simplest case, one such sensor device according to the invention can be built using an optics module and an electronics module which are installed in the housing, depending on the installation position of the optoelectronic sensor device, in different orientations. In an essentially rectanguloidal optoelectronic sensor device with one narrow side and one wide side, thus, there can be an optics module both for emission and reception of light on the narrow side and also alternatively on the wide side.
As stated above, the optoelectronic sensor device under consideration has a transmitter, which is preferably made as a laser diode, and/or a receiver, which is preferably made as a large-area photodiode. When the optoelectronic sensor device has a transmitter, it is provided, according to one preferred development of the invention, that the transmitter is located in a receiving device which is provided in the optics module. In this way, on the one hand, very simple installation of the transmitter in the optics module is achieved, and on the other hand, when the transmitter is installed in the optics module, accurate positioning and secure retention of the transmitter in the optics module are ensured. When the optoelectronic sensor device has a receiver, it can likewise be located in the optics module; this has similar advantages to those described above with respect to the transmitter.
According to one preferred development of the invention, however, it is provided that the receiver is part of the electronics module. Especially in the case of a large-area photodiode as the receiver, an especially simple and mechanically less susceptible electrical connection of the receiver is possible, and in addition, it is possible to check and/or adjust the complete electronics unit before installation in the housing. Thus, an already completely checked electronics module can be installed in the housing. In this respect, it is preferably provided that the electronics module has all the components necessary for the optoelectronic sensor device.
The electronics module can have a conventional circuit board as the base on which the individual electronic components are mounted. However, according to one preferred development of the invention, it is provided that the electronics module has a flexible conductor film. Preferably, this conductor film can, moreover, be folded such that the conductor film can be fitted exactly into the housing of the optoelectronic sensor device after appropriate folding. By a correspondingly altered and matched folding of the flexible conductor film, adaptation to another housing or to a housing in which the optics module is installed differently is easily possible. Moreover, if the receiver in the form of a large-area photodiode is already located on the conductor film, by the corresponding folding of the conductor film or by another arrangement of the conductor film the photodiode can be located at different points in the housing according to different requirements for the optoelectronic sensor. Of course, it is also possible to locate the photodiode at different locations of the conductor film.
The optics module can be inserted into the housing of the optoelectronic sensor device in different ways. It is also possible, for example, to place the optics module on the inside wall of the housing and to cement it there, or to clamp it between two opposite walls. According to one preferred development of the invention, however, it is provided that, in the housing, there are receiving means, the optics module has engagement means and the optics module is attached in the housing by engagement of the engagement means in the receiving means. In this way, on the one hand, especially simple holding of the optics module in the housing is achieved, and on the other hand, thus, accurate and always reproducible positioning and alignment of the optics module in the housing are ensured.
The receiving means and the engagement means must, of course, correspond to one another. All types which prevent slipping of the optics module in the housing are possible for the receiving means and the engagement means. In particular, it is preferable if the receiving means and the engagement means are made as a tongue and groove system and/or the receiving means are made as holes and the engagement means accordingly are made as insertion pins. Especially secure holding is achieved when the engagement means are locked in the receiving means. If replacement of the optics module or modification of its arrangement or alignment in the housing is not desirable or necessary, in addition, the engagement means can be cemented in the receiving means.
It has already been stated that the housing can be made rectanguloidal, for example. If, generally speaking, the housing has two side walls at an angle to one another and if there is one light passage opening in one of the side walls, through which the light emitted by the transmitter or the light to be received by the receiver can pass, according to a preferred embodiment of the invention, it is provided that the engagement means of the optics module are made such that the optics module can be installed in the housing in at least two different orientations which correspond to the alignment of the optics module to the light passage opening which is provided in one side wall or the other. This development of the optoelectronic sensor device according to the invention thus makes it possible to have to manufacture only a single optics module which then can be installed in the housing in those orientations which differ from one another and which then correspond to the different installation situations, specifically the different directions into which light is to be emitted or from which light is to be received.
Alternatively, according to a preferred development of the invention, it is provided that the optics module in the housing is pivotally mounted around its lengthwise axis. If the optics module is installed in this way into the housing of the optoelectronic sensor device, with this optoelectronic sensor device, at least two different emission or receiving directions can be accomplished. If the housing has two side walls which are at an angle to one another, preferably perpendicular to one another, for the aforementioned use of the optoelectronic sensor device, a respective light passage opening is provided in each of the two side walls and the optics module is pivotally mounted in the housing such that, by turning the optics module, one of the two light passage openings can be chosen as the light passage opening which can be used for the optics module.
A more versatile application of the electronic sensor device can be achieved according to a preferred development of the invention by the two side walls of the housing which are at an angle to one another being connected to one another by means of a wall section shaped like cylindrical sector, in the two side walls and in the wall section shaped like a cylindrical sector, there is a continuous light passage opening and the optics module is pivotally mounted in the housing such that each area of the light passage opening can be chosen as the light passage opening which can be used for the optics module. In this way, an area for possible emission of light or reception of light can be achieved which extends over an angle of 90xc2x0. In particular, it is provided that the orientation of the optics module in the housing in the installed state can be manipulated from the outside, for example, using a screw which can be adjusted using a screwdriver.
Furthermore, the invention relates to an optoelectronic sensor device with a housing and a mounting element which is provided on the housing and with which the housing can be attached to the holding device, the mounting element having an undercut such that the mounting element, in cross section, on its end facing the housing, is narrower than on its end facing away from the housing.
It was noted above that one problem in optoelectronic sensor devices is their accurate and reproducible positioning when installed in a corresponding system. Occasionally, it is necessary to temporarily uninstall the optoelectronic sensor device in order to acquire, for example, access to an otherwise blocked area of the system. Here, it is desirable that the optoelectronic sensor can be easily uninstalled and then can be installed again reliably as the original installation situation and alignment of the optoelectronic sensor device are restored.
Accordingly, a further object of the invention is to provide an optoelectronic sensor device which enables simple, reliable and reproducible installation and alignment.
The optoelectronic sensor device in accordance with the invention with which the aforementioned object is achieved is characterized in that the side edges of the mounting element, on its end facing away from the housing, run at an acute angle to one another. If the optoelectronic sensor device according to the invention is mounted using this mounting device on a holding device which has a correspondingly shaped and dimensioned receiving device in the form of a receiving rail and its side walls preferably likewise run at an acute angle to one another, then, when the optoelectronic sensor device is pushed into the holding device, using the mounting element, exactly one position is defined at which the mounting element cannot be pushed further into the holding device since the width of the recess of the holding device, on the one hand, and the width of the mounting element, on the other hand, correspond exactly to one another. If the optoelectronic sensor device is always inserted up to this stop point, its positioning can be reproduced at any time. When this stop point is reached, according to one preferred development of the invention, then especially reliable and mechanically stable holding of the optoelectronic sensor device in this position can be achieved in that, on the bottom of the mounting element, there is a recess into which a catch device which is attached to the holding device can be engaged. Preferably, it is provided that the catch device is a spring, especially a bent leaf spring.
The undercut can have different shapes, for example, a T-shape. However, according to one preferred development of the invention, it is provided that the mounting element, in cross section, is dovetail-shaped and/or the side edges of the mounting element run to one another in a V-shape.
In particular, there are now a plurality of possibilities for embodying and developing the optoelectronic sensor device in accordance with the invention which are explained in the following detailed description of preferred embodiments of the invention with reference to the accompanying drawings.